The present invention relates to a method and apparatus for making braided intraluminal implants, and also to a mandrel construction particularly useful in such method and apparatus.
Intraluminal devices, such as stents, filters and diverters are increasingly being used as implants within an artery, vein, or other tubular body vessel for effecting various medical treatments of the body. One type of intraluminal implant used for this purpose is the braided type produced by braiding machines which interweave a plurality of filaments around a mandrel aligned with the braiding axis. At the time of implantation, the braided tube is of reduced diameter (e.g., by enclosing it within an outer constricting tube) to enable the braided tube to be fed (e.g., by a catheter) via the lumen to the implantation site. Upon reaching the implantation site the braided tube is expanded (e.g., by removing the outer constricting tube), thereby firmly fixing the braided tube within the vessel wall.
It has been found that the contact of the braided tube implant with the vessel wall is enhanced if the outer ends of the braided tube are outwardly flared. This has proved difficult to accomplish using conventional braiding machines and conventional mandrels.